This invention relates to a device for driving dot printing bars in a dot printer and more particularly, to a device for driving dot printing bars in a dot printer of the type in which the operation of an electromagnetic device is not directly utilized for driving a dot printing needle, but utilized as a printing control command for the dot printing operation. The dot printing bar drive device generally comprises dot printing bars, electromagnetic devices and operation members which normally operate periodically and in the drive device of the type, only when the electromagnetic device is supplied electric current thereto and provides attraction function, the bar springs out to the striking or dot printing position in a timed relationship to the periodically operable member.
There have been proposed and practically employed a variety of devices for driving dot printing bars in dot printers and in one of the prior art dot printing needle drive devices of the above type, the movable iron piece of an electromagnetic device is connected to a flexible or sheet metal dot printing bar at a point adjacent the rear end of the bar and the attraction function of the movable iron piece operates the bar directly so as to cause the bar to strike against a recording paper so as to effect dot printing on the recording paper.
However, the prior art dot printing bar drive device referred to hereinabove has the disadvantages that the attraction by the electromagnetic device itself serves as the force with which the dot printing bar strikes against the recording paper for effecting dot printing on the paper and/or that the electromagnetic device is inevitably required be constructed to have a large size because the movement stroke of the movable iron piece determines the spring-out or protruding distance of the dot printing bar resulting in a large size bar drive device.